An Augmented Reality (AR) application overlays three-dimensional artificial objects (e.g. computer-generated imagery, also called CGI) atop the real world. Realism and real-time performance are key criteria to assess AR applications. There are two types of AR devices: “optical see-through devices”, like smart-glasses for example and “video pass-through” devices, like smartphones or tablets for instance. The present disclosure relates to this second type of AR devices.
Video pass-through devices are apparatus equipped with a display screen, a camera and means for the user to control the pose (location and aiming direction) of the camera in real time. For example, smartphones and tablets are AR devices when running an AR application, using their front screen and their rear-facing camera. In this case, the user controls the camera pose by handling the device. The video captured by the camera is rendered on-the-fly on the screen. The AR application overlay virtual objects of an AR scene on the images of the video.
In certain optimal camera angles, the user may watch an entire AR scene. However, if the camera is too close from the location of the AR scene or if the aiming direction of the camera is not in the optimal direction, some of the AR objects are out of the scope of the camera. If the camera is too far from the location of the AR scene, AR objects are small and details may be not seeable on the screen. To resolve this problem, the user has to search for the optimal pose by himself. Such a solution is not satisfying because the user is not always aware that he is missing objects or details and because the search of the optimal pose is a tedious task which disturbs the pleasant use of the AR application.